Edit
I think it the case that Rooted Debugging is not available in a stable device. Confirmed here.
On a dev build.
My phone is unrooted; the above is a way of giving root to Android Debug Bridge only, on an unrooted (dev) device.
I do not quite understand why the command is written this way. I previously used the command from https://doc.e.foundation/support-topics/create-a-log.html.
I run $ adb logcat -d > logcat.txt to create a file called logcat.txt in the current folder.
However they ask for and I tested adb logcat >/tmp/logcat.txt I get permission denied as the file is going to the root of my system (did you look there?);
adb logcat >logcat.txt works but I have to press ^C to stop.
(There is also logcat -h – like all adb logcat commands only works with a device connected.)